Evidence map›Paper›PMID 41354687›Full record

ArticleScientific reports2025

On the coincidence between the close passage of HD7977 and the Pliocene-Pleistocene transition.

Zhuoya Cao, Abraham Loeb, Morgan MacLeod

Abstract read
In one paragraph

Article in Scientific reports, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Zhuoya CaoXingjian College, Tsinghua University, Beijing, 100084, China. zhuoyacaoly@gmail.com.
Abraham LoebInstitute for Theory and Computation, Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA, 02138, USA.
Morgan MacLeodInstitute for Theory and Computation, Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA, 02138, USA.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The Oort Cloud's dynamical evolution is significantly influenced by both the galactic tide and stellar flybys. This study investigates the particular case of HD7977's close encounter 2.47 Myr ago, which likely repopulated the Inner Oort Cloud and potentially triggered a significant comet shower on Earth. Our results demonstrate that the shower's intensity strongly depends on HD7977's impact parameter (b), with possible flyby distances ranging from 2,300 AU to ∼ 13,000 AU. For the closest approach ([Formula: see text] AU), the terrestrial impact probability of 1 km comets increases by an order of magnitude compared to the steady state, slightly exceeding the asteroid impact probability at this size scale. We propose an analytical method to compute the probability of comet showers impacting Earth, which saves considerable computation time compared to N-body simulations. We identify a threshold diameter [Formula: see text] km for which yields [Formula: see text] in our model, with [Formula: see text] following a logarithmic dependence on b. These findings suggest that HD7977's flyby may have caused an enhanced comet flux during the Pliocene-Pleistocene transition, which could plausibly be related to the environmental changes at this era.

Identifiers

PMID41354687
PMCPMC12764986

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.